I was just given a brand new Coleman Powermate 5000 Generator,from Home Depot. It has a Robin Subaru 10 hp OHC single cylinder engine (EX30D). I put in Castrol GTX 5w30 for the break in oil, and ran it for 45 minutes yesterday with no load. I will be using it primarily as a back up generator, so it will sit for long periods of time. Though I'll probably run it once a month or so. Should I stick with dino, or should I use a Synthetic. I thought the syn might be better, as it will sit for a while. And I also was wondering if I could use syn at the first oil change(20 Hours) or do I need to run dino longer for the break in?I plan on doing the first oil change at 20 hours, and doing 100 hour/1 year oci's there after per the manual suggestions.If I do go with syn, what should I use. I was thinking about PP 5w30, or M1 5w30. Thanks in advance for your advice.

Yes, flush the oil (change it when warm) a few times to rid of any metal shavings and from that point onwards, any motor oil other than straight weight or API SA/SB shall be fine. Most of these latest type air cooled 4-cyl engines such as Robin-Subaru, Honda, Yahama and Mitsubishis call for multiviscosity motor oil just like ordinary automobile engine does).

You can feed it with fancy full syn if it makes you feel better. I, for one, use Tech2000 full syn HDEO 15W40 on all my lawn mower, tiller, pressure washers, etc. and been doing well so far...

Check the "Lawn Mower and Small Engine" section. There are several threads on this topic. I plan to use a dino diesel rated 10w30 on my next OCI - trying to find Delo 10w30. I am currently using Citgo syn 10w30 since my last change 2 years ago - the generator is not used a lot.

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In the air cooled Honda's we run (not as big as your Robin), we use your typical 10W-30, same stuff as we run in our service vehicles. Some of these tools, like the big trencher, will sit for months at a time. Never seem to have a problem firing them up when we needed.

I have posted many times on this subject. Having seen (and fixed) many portable generators fail on dino 5-30 I suggest a synthetic of slightly higher viscosity.

Florida heat is tough, as is running an entire house on a 11hp generator. Example: my 2 air cooled Honda water pumps failed early with dino oil. 15W-50 M1 resulted in much longer engine life.

My Robin 11HP gen set has only seen M1 15W-50 with 50 hour oil changes. It has serious hours on it with 3 hurricanes and home construction, without any problems. The oil is even clean when drained.

Contrast that with the many failures (including my co-workers) run on thin dino oil. The engines get ultra hot, the oil gets very thin and the connecting rod bearing (really just an aluminum con rod) fails. Every time. This situation was repeated thousands of times here in hurricane central.

Remember that 500 degree cylinder head temps are the norm in air cooled engines under full overload. I have seen 280 crankcase temps with my digital thermometer.

You might consider this product also: http://www.amsoil.com/StoreFront/ase.aspx?zo=515729 . "A commercial grade formulation designed for hot temperature, severe service operation of small engines where routine maintenance is often difficult or infrequent."

Justin,I recently purchased a Subaru/Robin generator, so went though the same exersize. Subaru recommends a 10W-40 if the generator is going to be used above 90 degrees F. I chose Amsoil MCF, their 10W-40 Motorcycle oil. It had all the properties I was looking for including the enhanced corrosion protection. Pablo can set you up with this one too.

Robin recommends a 10W-30 for their engines at all temperatures except for their generators. It seems they prefer a heavier oil for the constant, high loads that a generator can put on the engine.

I would also suggest running it under varying loads up to 5K watts for another 45 minutes and changing the oil at 1.5 hours. The Robin engines won't have the silver soup that is often seen in B&S and Tecumseh engines. They do generate some brass colored particles during the first few hours, and a 1.5 hour change will get rid of ~90% of that. I used Delo 10W-30 for the break-in. Put 10-20 hours on it before swithching to synthetic (Robin's recommendation).

Ed

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Well, I ran the generator for about 1.5 hours yesterday.(Had to do my rear brakes and used it to power the air compressor) I figured i'd run it a little more before changing the oil. Then I changed the oil with Formula Shell 10w30 SM rated. The old oil had some brass colored particles in it.I originally chose the 5w30 because we have seen temps in the 7-20F degree range, and I had some left over from my camry lof. The Generator has approx. 3 hours on it now. How long should I run it on this Dino, before changing over to syn.I bought 1 more quart of Formula Shell 10w30, and a quart of Mobil 1 10w30. I wasn't sure if I should run it like another 2 hours on this, then another dino for 2? then Syn? or just go to syn after this run of dino? Should I run this dino for another 5 hours and change to syn? I dunno.